Night blindness

Night Blindness means inability to see well in dim light or in darkness, like at night time. It is commoner than one can expect it to be!

There are many causes of night blindness. Vit.A deficiency, Retinitis pigmentosa are the common ones.

Retinitis pigmentosa (RP)

Retinitis Pigmentosa is characterized by night blindness and black dotting of the fundus. the Optic Nerve becomes pale white, called Optic atrophy. 

When does it occur?

It starts at an early age, around 15 years and progresses into adulthood. There are many varieties, some begin earlier and progress faster.

What is the cause?

It is a genetic disease and runs in families.

What happens in it?

Initially there is slight difficulty in seeing in dim light or night blindness, later this progresses. The field of vision becomes narrow. Later, limitations in day vision and Complete blindness can occur.

Some types of RP are associated with Deafness, Heart disease, Muscle disease.

Are any medicines available?

Many treatments like Vit A tablets etc. are being given, but their definite effect has not been documented. Some surgeries like retinal transplants are also being done  but they are still in  experimental stage today.

Devices for improved night-vision work may be helpful.